Non-invasive inspection
US4983841A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 1989 |
| Grant date | Jan 8, 1991 |
| Priority date | — |
| Expiry date | Sep 26, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2223/419
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Residual core material can be detected inside hollow cast articles using positron emission tomography. Positron radio-isotope material is inducted into any residual core material present by immersing a cast article in an aqueous solution of radio-isotope emitter, for example gallium. Absorbed gallium subsequently emits positrons which are annihilated in collisions with electrons emitting two 511 KeV gamma rays in diametrically opposite directions. The emissions are detected and tracked by a PET camera and the resulting images correlated with a sectioned image of the article as a check on the location of detected core material. Initially a low-dose-rate solution for the purpose of merely establishing the presence of core material is used but a second optional process step introduces a more active solution allowing a PET camera to collect sufficient data to image absorbed isotope.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.